Schedule Planning and Maintenance Activities Auxiliary Power Unit (APU) Boeing 737-500 Aircraft With Reliability Method

Penelitian ini bertujuan untuk merencanakan jadwal dan aktifitas maintenance yang yangefektif pada sistem auxiliary power unit sehingga tidak terjadi lagi kegagalan ataupun kerusakan yang tidak di rencanakan atau terjadi secara tiba – tiba. Kegagalan pada peralatan auxiliary power unit ada sering terjadi pada beberapa sistem kerja yaitu electrical system, Lubrication System dan Ignition System, di mana hal ini menimbulkan kerugian yang cukup besar bagi perusahaan penerbangan. Metode penelitian ini menggunakan pendekatan kualitatif dan kuantitatif, analisis kualitatif menggunakan metode Failure Mode Effect and Critically Analysis (FMECA) dengan menganalisis faktor – faktor penyebab kegagalan dan efek terjadinya kegagalan, dengan hasil penyebab kegagalan pada beberapa sitem kerja auxiliary power unit (APU) adalah sebagai berikut electrical system adalah pada komponen start Relay, Lubrication System adalah pada komponen Oil Filter, Ignition System adalah pada igniter plug. Dari hasil analisis FMECA tersebut di lakukan analisis kuantitatif dengan analisis dilakukan menggunakan metode reliability, parameter kehandalan dihitung dengan probabilitas distribusi Weibull, untuk menentukan batas kritis waktu operasional komponen ataupun part sistem yang merupakan batas kehandalan suatu sistem auxiliary power unit. Batas kritis operasional electrical system adalah sebesar 434 jam terbang, lubrication system adalah 1186 jam terbang, dan Ignition system adalah sebesar 1610 jam terbang, selanjutnya hasil tersebut di gunakan untuk menentukan jadwal maintenance yang efektif di dukung dengan perencanaan aktifitas maintenance yang tepat untuk menghilangkan penyebab – penyebab kegagalan pada peralalatan auxiliary power unit.

A cross-technology benchmark for incremental graph queries

To cope with the increased complexity of systems, models are used to capture what is considered the essence of a system. Such models are typically represented as a graph, which is queried to gain insight into the modelled system. Often, the results of these queries need to be adjusted according to updated requirements and are therefore a subject of maintenance activities. It is thus necessary to support writing model queries with adequate languages. However, in order to stay meaningful, the analysis results need to be refreshed as soon as the underlying models change. Therefore, a good execution speed is mandatory in order to cope with frequent model changes. In this paper, we propose a benchmark to assess model query technologies in the presence of model change sequences in the domain of social media. We present solutions to this benchmark in a variety of 11 different tools and compare them with respect to explicitness of incrementalization, asymptotic complexity and performance.

Definition of a Basic Design for Conversion of an Offshore Fixed Platform on a Depleted Reservoir Into a Sustainable Plant

In the framework of energy transition, a focus is given to the study of the conversion of offshore Oil&Gas platforms at the end of their life due to depletion of the reservoirs on which they operate. Their modular and versatile structure allows the implementation of new processes and innovative sustainable technologies for reducing the environmental impact of a complete decommissioning, especially on the subsea ecosystem that has grown around the jacket, and for guaranteeing costsaving solutions. Among different conversion options, this paper focuses on the installation on the platform of a system for the production of photovoltaic (PV) energy to be used for seawater desalination and its delivery to other platforms operating in the same area. The project focuses on the definition of technical characteristics of the basic design, on the investigation of the technical feasibility of the conversion process, on qualitative safety and environmental impact studies. Moreover, the old platform equipment to be decommissioned (ie. the equipment necessary for hydrocarbons treatment) are identified and the installation of new equipment is optimized, eg. the number of PV panels and, therefore, the installed power are maximized. At the same time, decommissioning costs and impacts can be minimized. The basic design is completed with a preliminary structural verification to guarantee that critical situations do not rise, with an indication on the main maintenance activities for the preservation of plant good efficiency and with safety and environmental preliminary analyses for the identification of potential criticalities to be managed at different design levels.

Fuzzy - Based Multi - Criteria Decision Support System for Maintenance Management of Wastewater Treatment Plants

Wastewater treatment plants (WWTPs) contain a large number of components, and these components in turn require a large number of maintenance activities and high costs. In this paper, a Fuzzy-based Multi-Criteria Decision Support System (FBMCDS) model was designed based on the failure mode and effect analysis FM-EA and applied to the Rustumiya Project (RP) in Iraq. Information of the RP’s components, failure modes, applied maintenance activities and costs were collected from the documented data, site visit and face-to-face interviews as well as opinions of 44 experts. Through applying the fuzzy logic to analysis the failure modes and effects, the risk priority index (FMRPI) and total intensity (FMTI) of each failure mode ware computed. Thus, maintenance priorities and weights of the RP’s failure modes were specified. In addition, the best maintenance plan was specified based on the FMRPI-FMTI diagram that shows the importance and the type of maintenance required for each failure mode. Failure of the submersible pump has the first rank in terms of priority, while the last priority was occupied by the building failure mode, where the mechanical failure modes are of the highest importance, followed by the electrical failure modes. Finally, the construction failure modes are ranked last due to the small probability of failure. The designed model is considered an efficient tool due to the similarity of the results with the reality of the situation and the ease of reading and displaying the results. In addition, this model can be applied to other projects such as water treatment plants and irrigation projects.

The Stakeholder Playbook for Explaining AI Systems

The purpose of the Stakeholder Playbook is to enable system developers to take into account the different ways in which stakeholders need to "look inside" of the AI/XAI systems. Recent work on Explainable AI has mapped stakeholder categories onto explanation requirements. While most of these mappings seem reasonable, they have been largely speculative. We investigated these matters empirically. We conducted interviews with senior and mid-career professionals possessing post-graduate degrees who had experience with AI and/ or autonomous systems, and who had served in a number of roles including former military, civilian scientists working for the government, scientists working in the private sector, and scientists working as independent consultants. The results show that stakeholders need access to others (e.g., trusted engineers, trusted vendors) to develop satisfying mental models of AI systems. and they need to know "how it fails" and "how it misleads" and not just "how it works." In addition, explanations need to support end-users in performing troubleshooting and maintenance activities, especially as operational situations and input data change. End-users need to be able to anticipate when the AI is approaching an edge case. Stakeholders often need to develop an understanding that enables them to explain the AI to someone else and not just satisfy their own sensemaking. We were surprised that only about half of our Interviewees said they always needed better explanations. This and other findings that are apparently paradoxical can be resolved by acknowledging that different stakeholders have different capabilities, different sensemaking requirements, and different immediate goals. In fact, the concept of “stakeholder” is misleading because the people we interviewed served in a variety of roles simultaneously — we recommend referring to these roles rather than trying to pigeonhole people into unitary categories. Different cognitive styles re another formative factor, as suggested by participant comments to the effect that they preferred to dive in and play with the system rather than being spoon-fed an explanation of how it works. These factors combine to determine what, for each given end-user, constitutes satisfactory and actionable understanding. exp

An Effective Digital Safeguarding System in University Libraries: A Model Plan

The purpose of the study is to present a model plan for developing an effective digital maintenance system with the help of institutional repository software in university library premises. This work is an investigative study of digital maintenance activities for sustainable development of the digital publications and intellectual outputs of universities in Bangladesh. The researchers investigated the university and university website and found that only 11% university libraries were active in preserving their digital resources while 89% of university libraries were either in the dark or less reluctant to adopt the system. Researchers realized that due to lack of proper guidelines and an ideal model plan, most of the university libraries were far behind in adopting a repository system for safeguarding their intellectual outputs. Hence this study describes a model plan for the university libraries of Bangladesh to create a sustainable preservation system easily and effectively. The model plan in this study was based on observation and review of the literature in the concerned field. All university authorities can follow the mentioned model for sustainable maintenance of their intellectual digital assets.

The impacts of the lack of ergonomic vision in mining equipment design projects on the health of workers in the maintenance sector

This study aims to analyze the impacts of the lack of ergonomic view in the projects of equipment design on workers’ health from the maintenance sector, in the mining industry context. To understand the operators’ health, maintenance activities of three types of equipment were analyzed: pump, crusher and sieve. The methodological strategy of Ergonomic Analysis of the Workplace (EWA) was used. Thus, changes in these activities are required, since some postures adopted for their performance were considered severe and with high risk. Bearing weight above the shoulders and uncomfortable positions are conditions resulted from failures in the equipment designs. To alleviate the problem, it is suggested the adoption of innovative tools or the creation of new supportive devices to improve working conditions of these maintenance professionals.